IBM retained its patent crown for 2011, topping the list of patent winners for the 19th year in a row. The only other U.S. company to make the top 10, Microsoft fell from third place to sixth place, according to data from IFI Claims Patent Services.

HP (1,308) and Intel (1,244) fell out of the top 10 and landed 14th and 16th, respectively, in IFI's list of the top 50 U.S. patent assignees.

According to IFI's count, the U.S. Patent and Trademark Office issued 224,505 utility patents in 2011, which is 2% more patents than were issued in 2010. While the total number of patents grants grew, there appears to be a slowing of patent growth among individual companies, IFI notes. Among the companies on its top 50 list, 16 produced fewer patents in 2011 than they did in 2010, including Cisco, HP, Intel, Microsoft and Oracle. By comparison, only one of 2010's top 50 companies received fewer than the prior year.

"Global companies, and especially Asian ones, are collecting U.S patents at a dizzying pace, and now Asian firms hold eight of the top 10 slots in the 2011 ranking," said Mike Baycroft, CEO of IFI CLAIMS Patent Services, in a statement. "This isn't to say that U.S. companies have lost their verve for patent production, as their patent portfolios are also growing. It seems that Asian companies have apparently made it a higher priority."

Asian firms account for 25 of the top 50 U.S. patent-grant recipients in IFI's ranking, and U.S. firms captured 17 slots.

Other trends of note:

* Apple moved up in the rankings to No. 39 (676 patents) after breaking into the top 50 for the first time in last year's list, when it debuted at No. 46.

* The wireless/mobile communications industry showed strong gains in patent grants, with Broadcom at No. 17 (1,164), Qualcomm at No. 26 (923) and Research in Motion at No. 40 (663)

* While IBM was granted more patents than Samsung, the pace of applications filed by Samsung is accelerating. Samsung's published pre-grant applications in 2011 numbered more than 5,600, compared to less than 5,000 for IBM.